of berlin



Patented Jan. 17, 1928.

UNITED STATES 1,656,239 PATENT OFFICE.

HALTER .SGHOELLEB AND KURT SCHMIDT, OF BERLIN, GERMANY, ASSIGNORS TO GHEMISCHE EABRTK AUF ACTIEN (VORM. E. SCHERINGJ, 0F BERLIN, GERMANY.

GPMPOSITION OF- MATTER AND PROCESS OFMAKING-SAME.

No Drawing. Application filed March 4, 1926, Serial I To 92,865, and in Germany March 10, 1926.

wherein a; may be a halogen and y a halogen or hydrogen, or w a halogen or hydrogen and y a halogen, while 2 is an aliphatic acid radical.

Our invention also includes the method of producing such compounds.

We have found that ox1ndol-3-acetic (Chemisches Zentralblatt1923 vol. 3 pge.

58) and its homologues can be halogenated in the aromatic nucleus without suffering any decomposition by melting corresponding halogenated oxindol aldehydes with malonicacid and treating the non-saturated carboxylic acids thus obtained with reducing agents.

Ewample 1.

1 mol oxindol-3-propionic acid, which is obtained by melting together molecular quantities of oxindol aldehyde and malonic acid and reducing the reaction product, is

suspended in an excess of concentrated hydrochloric acid and is treated with 1 mol iodine chloride in concentrated hydrochloric acid. The reaction product is allowed to restsome hours at ordinary temperature, whereupon it .is poured into' a great quantity of water, from which separates out after sometime the slightly brownish colored monoi-odine oxindol-EI-propionic acid.

CH-CHrCHrC Q01]:

224 and forming a yellowish-brown microcrystalline powder which is comparatively readily soluble in alcohol and glacial acetic acid and has properties similar to those of iodine oxindol acetic acid.

' Example 2.

dol-S-acrylic acid obtained is recrystallized from alcohol and glacial acetic. acid. The

solution of the sodium salt of this acid is then treated with a reducing agent, preferably with aluminium amalgam and the monoiodine oXindol-3 propionic acid obtained see Example 1) is treated further in a well nown manner.

Example Diiodine 'oxindol aldehyde is melted together with malonic acid and-treated fur-, ther as described with reference to Example 2, by treating the diiodine oxindol-3-acrylic acid thus formed with a, reducing agent, there is obtained the diiodine oxindol-3- propionic acid BOY! which, onbeing recrystallized from glacial acetic acid forms a light-brown 'microcrystalline powder which decomposes at 216 C., readily dissolves in alcohol and I glacial acetic acid, less readily in acetone and ether and in almost insoluble in cold and hot water.

We wish it to be understood that we do not desire to be limited to the particular thio naphthen carboxylic acid to compounds above described nor to the character and sequence of operations, to the quantities, temperatures and other figures mentioned in the foregoing description beyond what is claimed in the appended claims.

.1. As a new composition of matter, an oxindol-3-carboxylic acid halogen-substituted in the aromatic nucleus, being characterized by the formula CH-CHh-CHrC o 011 I NH 1/ wherein m may be a halogen and y a halogen CH-OHI-CH!C OOH being a light-brown microcrystalline powder which decom oses at 216 C., readily dissolves in alco 01 and glacial acetic acid, less readily in acetone and ether and is almost insoluble in cold and hot water.

4. The method of producing an 'oxindol- 3-carboxylie acid halogen-substituted in the aromatic nucleus, comprising melting the corresponding halogen-substituted oxindol aldehyde with the molecular quantity of malonic acid and treating the reaction product with a reducing agent. i

5. The method of producing di-iodineoxindol-3-propionic acid comprising melting diiodine oxindol aldehyde with the molecular quantity of malonic acid to form diiodine oxindol-3-acrylic acid and treating this product with a reducing agent.

In testimony whereof we aifix our signatures.

WALTER soHoELLER. KURT SCHMIDT. 

